Emergency locking device for safety seat belt used in motor vehicles and the like

ABSTRACT

An improvement in an emergency locking device for a safety seat belt in which a webbing roller is locked against rotation in the uncoiling direction as it is about to rotate at a speed higher than a certain predetermined value as a result of a sudden uncoiling or protracting movement of said safety belt.

Unite Sttes i tet 1 Hayashi et a1.

EMERGENCY LOCKING DEVI CE FOR SAFETY SEAT BELT USED IN MOTOR VEHHCLESAND THE LIKE Inventors: Yoshihiro Hayashi, Toyota;

Masahiro lwatsuki, Anjo, both of Japan Kabushiki-Kaisha Tekai Rika DenkiSeisakusho, Aichi-ken, Japan Filed: Get. 12,1971

Appl. No.: 188,141

Assignee:

Foreign Application Priority Data Oct. 20, 1970 Japan 45-104208 Oct. 20,1970 Japan 45-10-4210 U.S. (31.... 242/107.4, 188/8277, 200/6158 SB Int.C1 A621) 35/02, B65h 63/04 Field of Search 242/107.4, 107.3, 107 SB,

242/107 K; 280/150 SB; 297/386, 387, 388;

References Cited UNITED STATES PATENTS 10/1972 Kirchhoff 242/1074 Jan.22, 1974 2,708,555 5/1955 Heinemann et a1 242/107.4 3,214,218 10/1965G111 242/107.4 3,416,747 12/1968 Stoffel 242/107.4 2,953,315 9/1960Lautier et a1. 242/1074 3,064,920 11/1962 Cushman et a1. 242/10743,421,605 1/1969 Hansen 242/107 4 912,504 2/1909 Steckel et a1. 310/105Primary Examiner-John W. Huckert Assistant ExaminerJon W. HenryAttorney, Agent, or Firm-Sh1esinger, Fitzsimmons & Shlesinger 5 7]ABSTRACT An improvement in an emergency locking device for a safety seatbelt in which a webbing ro11er locked against rotation in the uncoilingdirection as it is about to rotate at a speed higher than a certainpredetermined value as a result of a sudden uncoiling or protractingmovement of said safety belt.

3 Claims, 6 Drawing Figures PATENTED JAN22 I974 SHEU 2 BF 2 IN VENTORSyoshihirb H y k a.n4L

a Z /w M M 1% m H I M M @ATTORNEYS EMERGENCY LOCKING DEVlCE FOE SAFETYSEAT BELT USED IN MOTGR VEll'llQLES AND TEE LIKE This invention relatesto an improvement in an emergency locking device for a safety seat beltwhereby a webbing roller is locked against rotation in the uncoilingdirection as it is about to rotate at a speed higher than a certainpredetermined value as a result of a sudden uncoiling or protractingmovement of said safety seat belt.

In the accompanying drawing illustrative of two preferred embodiments oftheinvention;

FIG. 1 is a partly cut front sectional view taken on the line 1-1 inFIG. 2,

FIGS. 2 and 3 are sectional side elevational views taken on the lineII-Il of FIG. 1, and illustrating the present device in the unlockingand the emergency locking conditions, respectively,

FIG. 4 is a sectional side elevation taken on the line IV-'lV of FIGS. 1and 6,

FIG. 5 is a perspective view of a spring constituting a springconnection means as used in the present invention, and

FIG. 6 is a view similar to FIG. 1 and showing an alternative embodimentof the invention in a partly out front view.

The first embodiment of the invention will now be explained by referringespecially to FIGS. 1 to 5 of the accompanying drawing.

The numeral 1 denotes a cylindrical housing of the webbing roller, tothe ends of which are fixedly fitted saucer-shaped side walls 2, 3. Awebbing roller 5 is passed rotatably through the center of housing 1 andsecured at one end to a safety seat belt 4. A coil spring 6 is mountedto the outer side of the side wall 2 so as to urge the seat belt 4 torotate in the retracting direction. Safety seat belt 4 is pulled outfrom an exit opening 7 on the housing 1. This housing 1 houses thepresent device in its entirety and constitutes a mounting means forsecuring the device to the floor of a motor vehicle. The numeral 9denotes a control plate for pawl members 15 fixedly fitted to thewebbing roller 5 at the outer side of the side wall 3. Said controlplate has a pair of recesses 10 on its circumference. The numeral 13denotes a rotatable operating member loosely fitted on webbing roller 5at the outer side of said control plate 9 by means of a boss 14 so as tobe freely rotatable about webbing roller 5. Said operating member 13mounts pivotally said L-shaped pawl members 15 by means of mountingshafts 1.?6. Each of said recesses lit) on said control plate 9comprises two continuous edge parts 11 and 12 adapted respectively tocooperate with two opposite sides of an arm portion 17 of a pawl member15. Numeral l8 denotes a number of teeth arranged in a circle on theinner peripheral part of said side wall 3. The tooth flank of each ofsaid teeth 18 is adapted for engagement with the foremost part of eachpawl member 15. Numeral 20 denotes a spring secured at its two ends toopposing surfaces of said control plate 9 and operating member l3 a ndadapted for coupling them together in either direction of rotation. Saidspring 20 constitutes an elastic or spring coupling means-for causingsaid operating member 33 to rotate at the same speed of rotation as saidwebbing roller 5 and in synchronisni therewith under normal operatingconditions of the present emergency locking device. It

will be readily understood that the operating member 13 is resilientlyurged to move in the direction of working force of the spring 20 andeach pawl member 15 normally is kept in close contact with one of theedges ll of one recess 110 on the control plate Q as will be seen fromFIG. 2. l awl member B5 is thus normally out of engagement with teeth 18formed on the inner periphery of the side Wall 3.

Numeral 121i denotes an elastic body made from rubber in the form of abellows and fixedly fitted at its inner end to said boss 14 of saidoperating member 13. Said elastic body 21 is also formed at itsoutermost part with a radial extension constituting a brake disc 22, theperipheral part of which is formed into a friction ring part 23 ofconsiderable thickness. Numeral 24 denotes a cover fitted to the sidewall 3 and formed with friction braking surfaces 25, 26 adapted toreceive said ring part 23 and it also facing to said ring part 23.

The operation of the first embodiment of the invention is as follows:

Operating member 13 is fitted around webbing roller 5 for free rotationthereabout and coupled thereto through said control plate 9 under theaction of spring 20 constituting an elastic or spring coupling means.When safety seat belt 4- is protracted at a lower speed, said operatingmember 13 will rotate at the same speed of rotation as said webbingroller 5 and with one of the edges 1 ll of each recess it on the controlplate 9 in engagement with pawl 15, as will be seen from FIG. 2. Saidpawl member 9 will thus be kept in rotation without any mechanicalengagement between its pawls and teeth 18 formed on the side wall 3.

When the passenger in' a vehicle wears safety seat belt 4 in theprotracted condition and the vehicle is subjected to sudden accelerationas a result of sudden brake application or collision, safety belt 4 willbe protracted rapidly by the inertia motion of the passengers body.Webbing roller 5 will thus rotate in the direction of protraction at arotational speed higher than its normal value. Said elastic body 21 willbe subjected to flexure instantaneously owing to a sudden shock appliedto the vehicle, and the brake disc 22 will be tilted. Thus, the frictionring 23 will be brought into contact with friction brake surfaces 25 or26 or both, thus braking the operating member 13 against furtherrotation. There is thus induced a differential motion between saidmember 13 and the control plate S, which is always kept in synchronousrotation with webbing roller 5. The control plate 9 will rotate fasterthan said member 13 and each pawl member 15 pivotally mounted to saidoperating member will abut with one of its edges against the edge 12 ofthe associated recess 10 on the control plate 9. The foremost part ofsaid pawl member 15 will thus be projected radially and brought in meshwith one of the teeth l8 formed on the side wall 3, as illustrated inFIG. 3. Thus, the webbing roller 5 is immediately locked againstrotation in the direction of protraction of seat belt 4 through themedium of the control plate 9.

As will become obvious from the foregoing description of the firstembodiment, when a rotatable operating member fitted on the webbingroller for free rotation thereabout and coupled operationally so as tomake synchronous rotation therewith is subjected to a sudden effort as aresult of deceleration or acceleration induced by sudden braking orcollision or hitting of the vehicle from behind by another vehicle, thesafety seat belt 4 will be suddenly and rapidly protracted, at the sametime that a brake disc coupled to said operating member will be tiltedor displaced axially, thus inducing a braking operation. This brakingeffort will then be transmitted to said operating member and there isthus caused a differential motion between the latter and the Next, thesecond embodiment of the invention will be explained by referring toFIG. 6. In this FIG. 6, parts and members denoted by the referencenumerals 1 to 26 are the same in construction as those already explainedby refernce to FIGS. Ito 5.

Numeral 27 in FIG. 6 denotes a brake disc jointed and se-cured to theouter surface of the rotatable operating member 13. Numeral 28 denotesan electromagnetic coil placed in opposition to said brake disc 27 and acoil casing 29 is fixedly fitted in the side wall 3. Numeral 30 denotesan acceleration switch of the known construction adapted to be turned onwhen it has sensed acceleration or deceleration which is higher than apredetermined value. This switch 30 is placed in an electric circuitadapted for energizing an electromagnetic coil'28. This electromagneticcoil 28 constitutes an example of the electromagnetic braking device tobe utilized in the present second embodiment. This braking device can beso designed that the brake disc 27 is pressed for performing a brakingoperation upon energization of such braking device.

The operation of this second embodiment is as follows: i

As already described, the operating member 13 is fitted around webbingroller for free rotation thereabout and coupled therewith throughcontrol plate 9 under the action of a spring 20 constituting an elasticor spring coupling means. When safety seat belt 4 is protracted at aslow speed, such operating member 13 will rotate at the same speed ofrotation as said webbing roller 5 and with one of the edges of the armpart 17 of each pawl member 15 in close contact with the edge 11 of theassociated recess on the control plate -9, as will be supposed from FIG.2. Each pawl member will thus be kept in rotation without any mechanicalcollision between its foremost part and said teeth 18 formed on the sidewall 3.

When the passenger in a vehicle wears safety seat belt 4 in a protractedcondition, and a sudden deceleration is caused to the vehicle as aresult of a sudden braking or collision, seat belt 4 will be protractedat an enhanced speed by the inertia motion of the passengers body.Simultaneously, acceleration switch 30 will come in operation andenergize electromagnetic coil 28. Magnetic lines of force will thus beproduced and attract brake disc 27 for performing a braking operation.The braking effort thus produced will be transmitted to the rotatablemember 13. There is thus induced a differential motion between saidrotatable member 13 and the control plate 9 which is kept in synchronousrotation with said webbing roller 5. The control plate 9 will rotatefaster than said rotatable member 13, and each pawl member 15 pivotallymounted on said member 13 will thus abut with one of its edges againstthe edge 12 of the recess 10 on the control plate 9. The foremost partof each pawl member 15 will thus be projected radially and brought intomesh with one of the teeth 13 formed on the side wall 3, as illustratedin FIG. 3.

According to this second embodiment, a rotatable operating member isfitted freely on a webbing roller and adapted normally for rotation atthe same rotational speed as said webbing roller by the elastic orspring coupling device. There is mounted a brake plate to this operatingmember capable of performing a braking action through energization ofthe braking electromagnetic device. When sudden deceleration oracceleration is applied to the vehicle, acceleration switch will come inoperation instantaneously and energize said electromagnetic device so asto exert a braking effort to said operating member. Thus, as a result ofsuch acceleration, safety seat belt is protracted and there is caused adifferential motion between said operating member and said webbingroller. Thus, a differential motion caused by the instantaneousoperation of the braking electromagnetic device is utilized for lockingpositively said webbing roller against rotation in the direction ofprotracting safety belt 4. Thus, by using an acceleration switch ofreliable operation, locking operation can be obtained rapidly andaccurately for protection of the passenger against serious risk owing toan inertia motion caused by the sudden vehicle acceleration ordeceleration.

What is claimed is:

l. An emergency locking device for a safety seat belt comprising arotary webbing roller,

an operating member rotatable on said webbing roller,

elastic coupling means normally coupling said operating member to saidwebbing roller so that said operating member normally performs asynchronized rotation with said webbing roller,

a braking plate connected to said operating member,

a stationary surface adjacent said plate,

a centrally arranged flexible elastic body between said plate and saidoperating member and which flexes upon rotation of said roller in excessof a predetermined value to urge said brake plate against saidstationary surface thereby effecting relative rotation between saidoperating member and said roller,

a pawl member pivotally mounted to said operating means on said controlplate for engaging said pawl member upon rotation of said control platerelative to said operating member to pivot said pawl member on saidoperating member to project said pawl member into engagement with atooth of said stationary member to effect a braking action on saidroller.

2. An emergency locking device for a safety seat belt comprising,

a webbing roller,

an operating member rotatable on said webbing roller,

elastic coupling means normally coupling said webbing roller to saidoperating member so that said operating member normally performs asynchronized rotationwith said webbing roller,

a brake plate secured to said operating member,

a braking electromagnetic device mounted in opposition to said brakeplate and operative when energized to brake said operating member,

a pawl member pivotally mounted on said operating member,

a stationary member having a number of teeth thereon arranged inangularly spaced relation in a circle around said operating member andin opposition to, and normally disengaged from, said pawl member,

a control plate fixedly fitted to said webbing roller,

means on said control plate for pivoting said pawl member into lockingengagement with one of said teeth when a differential motion betweensaid control plate and said operating member is caused by the braking ofsaid operating member, and

an electric circuit including an acceleration switch connected incircuit with said electromagnetic device and operative upon accelerationof said control plate higher than a predetermined value to energize saidbraking electromagnetic device to cause said pawl member to move intolocking engagement with one of said teeth.

3. An emergency locking device for a safety seat belt,

comprising a rotary webbing roller,

a rotatable operating member loosely fitted on said webbing roller,

a control plate fixed to said webbing roller,

a pawl pivotally mounted on said operating member and engaged with saidcontrol plate for pivotal movement thereby upon relative rotationbetween said control plate and said operating member,

resilient means coupling said operating member with said webbing roller,

a brake plate secured to said operating member,

a fixed member surrounding said operating member and coaxial with saidwebbing roller and having a plurality of internal teeth arranged aroundsaid operating member for engagement by said pawl, and

W means for applying a braking force to said brake plate when saidwebbing roller is rotated at an acceleration in excess of apredetermined value to produce relative rotational motion between saidcontrol plate and said operating member to cause said pawl to pivot onsaid operating member into engagement with a tooth of said fixed memberto lock said webbing roller against rotation,

said pawl being pivoted intermediate its ends on said operating member,

said control plate having a peripheral notch in it wherein one end ofsaid pawl engages, said end normally engaging against one side of saidnotch, and i said notch having an angular width greater than the angularwidth of said one end so that when said relative rotational motionoccurs the other side of said notch engages said pawl to pivot said pawlso that its other end engages a tooth of said fixed member.

1. An emergency locking device for a safety seat belt comprising arotary webbing roller, an operating member rotatable on said webbingroller, elastic coupling means normally coupling said operating memberto said webbing roller so that said operating member normally performs asynchronized rotation with said webbing roller, a braking plateconnected to said operating member, a stationary surface adjacent saidplate, a centrally arranged flexible elastic body between said plate andsaid operating member and which flexes upon rotation of said roller inexcess of a predetermined value to urge said brake plate against saidstationary surface thereby effecting relative rotation between saidoperating member and said roller, a pawl member pivotally mounted tosaid operating member, a stationary member surrounding said operatingmember and coaxial with said webbing roller and having a number ofinternal teeth arranged in a circle around said operating member inopposition to said pawl member and normally disengaged therefrom, acontrol plate fixedly fitted to said webbing roller, and means on saidcontrol plate for engaging said pawl member upon rotation of saidcontrol plate relative to said operating member to pivot said pawlmember on said operating member to project said pawl member intoengagement with a tooth of said stationary member to effect a brakingaction on said roller.
 2. An emergency locking device for a safety seatbelt comprising, a webbing roller, an operating member rotatable on saidwebbing roller, elastic coupling means normally coupling said webbingroller to said operating member so that said operating member normallyperforms a synchronized rotation with said webbing roller, a brake platesecured to said operating member, a braking electromagnetic devicemounted in opposition to said brake plate and operative when energizedto brake said operating member, a pawl member pivotally mounted on saidoperating member, a stationary member having a number of teeth thereonarranged in angularly spaced relation in a circle around said operatingmember and in opposition to, and normally disengaged from, said pawlmember, a control plate fixedly fitted to said webbing roller, means onsaid control plate for pivoting said pawl member into locking engagementwith one of said teeth when a differential motion between said controlplate and said operating member is caused by the braking of saidoperating member, and an electric circuit including an accelerationswitch connected in circuit with said electromagnetic device andoperative upon acceleration of said control plate higher than apredetermined value to energize said braking electromagnetic device tocause said pawl member to move into locking engagement with one of saidteeth.
 3. An emergency locking device for a safety seat belt, comprisinga rotary webbing roller, a rotatable operating member loosely fitted onsaid webbing roller, a control plate fixed to said webbing roller, apawl pivotally mounted on said operating member and engaged with saidcontrol plate for pivotal movement thereby upon relative rotationbetween said control plate and said operating member, resilient meanscoupling said operating member with said webbing roller, a brake platesecured to said operating member, a fixed member surrounding saidoperating member and coaxial with said webbing roller and having aplurality of internal teeth arranged around said operating member forengagement by said pawl, and means for applying a braking force to saidbrake plate when said webbing roller is rotated at an acceleration inexcess of a predetermined value to produce relative rotational motionbetween said control plate and said operating member to cause said pawlto pivot on said operating member into engagement with a tooth of saidfixed member to lock said webbing roller against rotation, said pawlbeing pivoted intermediate its ends on said operating member, saidcontrol plate having a peripheral notch in it wherein one end of saidpawl engages, said end normally engaging against one side of said notch,and said notch having an angular width greater than the angular width ofsaid one end so that when said relative rotational motion occurs theother side of said notch engages said pawl to pivot said pawl so thatits other end engages a tooth of said fixed member.